Nutrient Uptake and Yield of Physic Nut (Jatropha curcas L.) as Affected by Nutrient Source and Intercropping

Abstract

Optimum species combination in intercropping would optimize the benefits of competitive interactions based on resource availability. Field trials were conducted between July 2019 and November 2020 at the Institute of Agricultural Research and Training research station, Ikenne, Ogun State, Nigeria to examine the effects of fertilizer application and intercropping on the nutrient uptake and yield of Jatropha curcas. The experiment was a split-plot arrangement in a Randomized Complete Block design, replicated three times. Main plots were fertilizer type (control; NPK (20:10:10); organic; 50% organic + 50% NPK), with sub plots of sole Jatropha; sole okra; Jatropha/okra intercrop. Nutrient uptake was determined at the onset of flowering, while the number of seeds and seed yield per hectare were assessed at fresh fruiting stage. Seed yield, N, P and K uptake were similar in sole and intercropped Jatropha even though more N and K were absorbed than P. Okra can be intercropped with Jatropha with no significant reduction in okra yield as the fruit yield in both intercrop, 2791.36 kg/ha and monocrop, 3305.39 kg/ha were comparable. Uptake of N (145.9 g/kg), P (4.9 g/kg) and K (69.24 g/kg) was significantly highest from organic source. Organic +NPK source had almost similar but lower values of N (138.1 g/kg) and P (4.25 g/kg) and K (55.04 g/kg) uptake than organic source but were significantly higher than the control which had lowest nutrient uptake. Jatropha seed yield was increased significantly by fertilizer application. Application of organic + NPK fertilizer produced significantly highest seed yield of 88.85 kg/ha and 92.02 kg/ha during the 1st and 2nd harvest cycle, respectively. This was followed by organic fertilizer application (52.35 kg/ha and 53.39 kg/ha). The least was from the control treatment with 13.12 kg/ha and 14.02 kg/ha during the 1st and 2nd harvest cycle, respectively. Since nutrient uptake of Jatropha was not affected by intercropping, Jatropha-okra intercrop can be adopted with the use of organic +NPK to sustain productivity.